Imprbvemenit in heaters



i M. FUND.

HotfAirv Furnace. A f

Ptentedlune 10. 1862.

Ziyi

N. PETERS PhuwLitlwgnpher. wnshingmn. n. c.

^ MOSES POND, on BOSTON, MASSACHUSETTS.

l. t Specification forming-part of Letters Patent No. 35,514.11, dated une 10, 1862.`

i' `Beit known that I, MOSES POND, of Boston, in the countyof Suffolk and State of Massachusetts, have invented a'newand Improved Mode of Constructing HotAir Furnaces and` Stoves, of which the following is a`full',.c1ear, and exactdescription, `reference being had to `the accompanying drawings, making part of this specification, in whichw- Fig. 3 is Fig. 4 is .a larger View of tral sectiou` of one ot' the pipes at its lower mouth `ou the lineaire of Fig. 2.`

I have long `observed that much of the heat evolved, in afurnace` escapes through the smokepipe to the chimney and is' lost to use `from the` difliculty of bringing enough-radiating-surface near the tire.

The object of this invention is to economizc y a portion of such heat, otherwise wasted, by

f the following apparatus. l

Intp thedrum or domeof the furnace I introduce one or more suitably-prepared tubes orpipes, of iron or other material, `which pipes` are so arranged asto convey external air up into the dome and over the fire, where it b'e` comes heated, andthenceinto the airchamber,

. where it mingleswith the .hot air which has been thrown oft', as in ordinary4 furnaces, by y radiation.

In ordinary furnaces heat is prov cured by radiation from the outer surface of the dome; but my invention, while not dimin- .ishing anyof the caloric volume so obtained, increases it by'the quantity which is carried through the interior pipes, before referred to,

and discharged into the air-chamber.

' wayitadds to1 the efficient heatproducing` In this power of the'furhaee;v These pipes are now `so .perfected as to obviate three objections, l which I at first metin attempting to use them,

and hence may be said to possess at least three advantages, as follows: First, the necessary expansion and contraction of thel pipes from i becoming hot and cold, and their consequent displacement and danger of cracking, are provided for; second, the gases and smoke are prevented from escaping around `the pipes into the archamber; third, the pipes can be taken out and replaced at pleasure.

I now proceed to a more speciiic description of the pipes and their method of operation,

x `by the aid of drawings taken from thevmodel. Figure lis a top view of the drum or dome `of a furnace containing my improvements.

` "Fig, 2 is a `vertical transverse and central section (on the line y' y of Fig. 1) ofthe dome i and of oneof thepipes therein contained, more particularly described hereinafter. an amplified view of the upper portion of one fof the pipes, embracing its cup and the parts `adjacent thereto. v the flange `or collar, of which three are represented iu Fig. 1. Fig. 5 is a horizontal cen-` In the drawings, M is the mouth of the furnace; R,`the lower ring or rim of its dome, which rests on the tirepot, containing the burning fuel. I?, P,'and I are three of the pipes to be described; T, the top of the dome, above and aroundv whichy is the air-chamber; S, the Smoke-pipe. f

Each pipe `is constructed and adjusted as follows: Beginning at its lower end, at the lower part of thedome, Figs.4 5 and 2, A represents the mouth of the pipe, open to the outer air. d d is the line of the'portion of the dome adjacent to the mouth of the pipe. Around this mouth A, on the exterior surface of the dome, runs a circular flange, ff', with a rim, r r', reaching into thepipe. Inside the dome .the pipe has a shoulder, g g', terminating ina flange, h h', which laps along the inner surface of the dome a a', /around'the pipe, asthe outer iiange,ff, does along its exterior. `The pipe, the shoulder g g', and flange h h are cast in one piece, and the outer ange, ff', with its rim rr', in a second pieoe,which lmethodol" casting will be found the best. The pipe, thus armed with its shoulder g g'and ange h 71.',-is secured to the outer ange,ff, and its rim r r by bolts B B', eachv consisting of a nut and screw. These bolts run through the twoiianges and the dome and bind all three tightly together. Moreover, between the -shoulder g g and the rim r r is spread, i

thus the joint is bolted airtight. The pipe thence leads up the dome through au aperture (whose diameter is the line Z Z) in its top T, and opens into the air-chamber. If the position of the pipe were unaffected by the heat of the fire, this aperture Z Z might be cut to tit the pipe, and the latter secured im movably to the top; but the pipe when heated must expand, and in expandingis thrown forward or inward toward the center ofthe dome by a considerable amount. It is obvious, therefore, that with this constant pressure inward by heat and shrinking outward or backward by cooling again the pipe would soon loosen in its upper socket, or break, and the gases would escape around it into the hot-air chamber,

and thence ascend by the various conduits toA the building above. To remove this difficulty I introduce an expansion and contraction joint, with its accompanying contrivances, (Figs. 3 and 2 chietly,) as follows: Near the top of the dome, but before the pipe emerges therefrom, is a shoulder, 'it/Y, running round the pipe, on which rests a cup, C. This cup C may be cast solid on the pipe with it and the shoulder, but it will more easily be cast separate and set upon the shoulder. This cup, too, may be of any suitable size, so that it does not interfere with the other cups, and allows the pipe full liberty to play forth and back in its expansions and contractions. With the cup is connected another contrivance, as follows: On the exterior surface of the top of the dome, and near the top of thek pipe which it surrounds and to which it is suitably fitted, is a movable plate or follower, N N N, Figs. 1, 2, or 3, whereof Fig. 4 is a larger projection. In the drawings, this follower or collar, as we may properly style it, is a circular flange similar in general shape to the immovable flangeff at the other extremity of the pipe, and fastened to the dome by bolts b b similar to the bolts B B; but this collarN (N or N) is cut with two oblong slots, KK', by which the collar may play between the bolts and the dome, to which the bolts secure it; hence whenever the pipe eX- pands the movable collar N follows it along, sliding on the dome by the aid of the slots. It has just been said that the collar is suitably fitted to the pipe; butit must not sit so tightly as to impede the pipe inthe expanding of the latter upward on being lengthened by the heat.

3 and 2, which is cast solid with the top ofthe dome and projects downward therefrom into the cup, not entirely reaching its bottom. The cup is nearly filled with sand, (represented by the black dots in Figs. 3 and 2,) and inside the rime e the sand is filled higher up toward the top of the rim and the dome and the movable collar N However, the sand will soon reduce and level its inequalities in height inside and outside the rim by its own shit'tings. From this contrivauce it is apparent that the pipe may lengthen or shorten, may move forward or backward, asits expansion and contraction force it to move, and yet by the shifting of the sand inside the cup the joint at thetop between the pipe and the dome is always kept perfectly air-tight. It might Y conducting external air across the hot-air chamber into the lower mouths of these hotair pipes, now fully described.

What I claim as my invention, and desire to secure by Letters Patent, is

The upper joint of the pipe, consisting of the cup or its equivalent, with the sand and the collar N with its elongated slots KK and the rim projecting into the cup, or its equivalent, all constructed substantially as above specified andV operating as described, so as to allow the expansion and contraction of the pipe, and at the same time, by making the joint air-tight, to prevent gas and smoke from escapinginto the hot-air chamber.

MOSES POND.

In presence ot`- GEORGE E. POND, FRANoIs V. BALCH. 

